#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <cstring>

int main(int argc, char *argv[])
{
    if (argc != 3)
    {
        std::cerr << "Usage: " << argv[0] << " server-ip server-port" << std::endl;
        exit(0);
    }

    std::string serverip = argv[1];
    uint16_t serverport = std::stoi(argv[2]);

    // 创建 socket
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);

    if(sockfd < 0)
    {
        std::cerr << "create socket error" << std::endl;
        exit(1);
    }

    // 2. 不需要显式地bind，但是一定要有自己的IP和port，所以需要隐式的bind，OS会自动bind sockfd，
    //用自己的ip和随机的port
    struct sockaddr_in server;
    server.sin_family = AF_INET;
    server.sin_port = htons(serverport);
    ::inet_pton(AF_INET, serverip.c_str(), &server.sin_addr);

    int n = ::connect(sockfd, (struct sockaddr*)&server, sizeof(server));
    if(n < 0)
    {
        std::cerr << "connect socket error" << std::endl;
        exit(2);

    }

    while(true)
    {
        std::string message;
        std::cout << "Enter #";
        std::getline(std::cin, message);

        write(sockfd, message.c_str(), message.size());

        char echo_buffer[1024];
        n = read(sockfd, echo_buffer, sizeof(echo_buffer));
        if(n > 0)
        {
            echo_buffer[n] = 0;
            std::cout << echo_buffer << std::endl;
        }
        else
            break;
    }

    ::close(sockfd);
    return 0;
}